Glucose-6-phosphate dehydrogenase deficiency

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Blood cells

Glucose-6-phosphate dehydrogenase deficiency

Definition:

G-6-PD deficiency is a hereditary, sex-linked enzyme defect that results in the breakdown of red blood cells when the person is exposed to the stress of infection or certain drugs.

Alternative Names:
G-6-PD deficiency; Hemolytic anemia due to G6PD deficiency; Anemia - hemolytic due to G6PD deficiency
Causes, incidence, and risk factors:

text continues below

G-6-PD deficiency is an inheritable, X-linked recessive disorder whose primary effect is the reduction of the enzyme G-6-PD in red blood cells, causing destruction of the cells, called hemolysis. Ultimately, this hemolysis leads to anemia -- either acute hemolytic or a chronic spherocytic type.

In the United States, many more black than white people have the disorder. Approximately 10-14% of the black male population is affected. The disorder may occasionally affect a black women to a mild degree (depending on their genetic inheritance).

People with the disorder are not normally anemic and display no evidence of the disease until the red blood cells are exposed to an oxidant or stress.

Drugs that can bring on this reaction include:

antimalarial agents
sulfonamides (antibiotic)
aspirin
nonsteroidal anti-inflammatory drugs (NSAIDs)
nitrofurantoin
quinidine
quinine
others

It can also be caused by exposure to certain chemicals, such as those in mothballs. The chronic spherocytic anemia is unaffected by exposure to these drugs.

The risk of acute hemolytic crisis can be decreased by reviewing the family history for any evidence of hemolytic anemias or spherocytosis or testing before giving any medications belonging to the above class of chemicals.

The episodes are usually brief, because newly produced (young) red blood cells have normal G6PD activity.

Risk factors are being black, being male, or having a family history of G6PD deficiency. Another type of this disorder can occur in whites of Mediterranean descent. This form is also associated with acute episodes of hemolysis. Episodes are longer and more severe than in the other types of the disorder.